code: def _unit_transform_test(
      self, unit, input_instance, expected_outputs
  ):
      outputs = unit.transform(input_instance)
      self.assertIsInstance(outputs, list)
      common_testing_lib.assert_set_equality(
          self, expected_outputs, outputs
      )
      self.assertEqual(unit.input_type, type(input_instance))
      if outputs:
          self.assertEqual(unit.output_type, type(outputs[0]))
  
file_path: magenta/magenta/pipelines/chord_pipelines_test.py
imports: from absl.testing import absltest
  from magenta.common import testing_lib
  from magenta.pipelines import chord_pipelines
  from magenta.pipelines import melody_pipelines
  from note_seq import chords_lib
  from note_seq import constants
  from note_seq import sequences_lib
  from note_seq import testing_lib
  from note_seq.protobuf import music_pb2
label_desc: Use image node_id 2 for calling the ChordPipelinesTest obj's underlying member method code with example usage: obj._unit_transform_test(unit, input_instance, expected_outputs) without return types